Researchers say they believe they have found the world’s largest canyon - located under the Antarctic ice.

Writing in the journal Geology, a team of researchers led by Durham University in England says satellite data reveal a possible canyon over 1,000 kilometers long and, in places, one kilometer deep, roughly the same depth as the Grand Canyon in the United States, but much longer.

The discovery still “needs to be confirmed by direct measurements,” according to the researchers.

“This is a region of the Earth that is bigger than the UK and yet we still know little about what lies beneath the ice,” said Stewart Jamieson, from the Department of Geography at Durham University. “In fact, the bed of Antarctica is less well known than the surface of Mars. If we can gain better knowledge of the buried landscape, we will be better equipped to understand how the ice sheet responds to changes in climate.”

The canyons, which are located in the remote Princess Elizabeth Land ((PEL)) region in East Antarctica, are actually chasms buried under kilometers of ice.

Researchers believe the canyons were carved by water, either flowing under the ice or perhaps by water that ran over the area before the ice formed.

While no part of the canyons can be seen, the surface ice does reflect the possible canyons below when using satellite imagery. The group also has identified small parts of the canyons using radio-echo sounding data, meaning radio waves are passed through the ice to map the rocks beneath.

Researchers say the canyons may be connected to a massive subglacial lake that could cover up to 1,250 square kilometers.

Currently, the team is conducting an airborne survey of the area using radio-echo sounding measurements in order to confirm the canyons’ presence. Those results could be made public later this year.